Which term describes an abnormal heart rhythm?

The term that best describes an abnormal heart rhythm is "arrhythmia." This term encompasses a wide range of irregular heartbeats that can occur due to various factors, including issues with the heart's electrical system. Arrhythmias can manifest in many forms, such as extra beats, skipped beats, or a heart rate that may be too fast or too slow.

While "dysrhythmia" can also refer to an abnormal rhythm, the term "arrhythmia" is more commonly used and understood in clinical settings. "Cardiac arrest" refers specifically to a situation where the heart stops beating effectively, leading to a cessation of blood circulation, which is distinct from having an abnormal rhythm. "Bradycardia" describes a specific condition characterized by a slower than normal heart rate, which can be a type of arrhythmia, but does not encompass the broader category of all abnormal heart rhythms. Thus, "arrhythmia" is the most accurate and widely accepted term for describing an abnormal heart rhythm.